SUPERSEDED — wrong protein (2026-10-10). The historical analysis below used human Q6ZT21 (TMPPE, 453 aa), not human CFAP418 Q96NL8 (207 aa). Its coiled-coil, WD40 and TPR conclusions do not establish CFAP418 function. The original report and analysis outputs are retained as historical provenance, not current evidence. The mouse FASTA was also mislabeled: its unchanged 363-aa sequence is Etnk1 (historical accession Q8BXQ0, now a secondary accession of Q9D4V0), not mouse Cfap418 Q3UJP5 (209 aa). Only that FASTA header has been corrected; no sequence was replaced. See the current source evidence and dated review notes.

CFAP418 Bioinformatics Analysis Results

Summary

Bioinformatics analysis of CFAP418 (Q6ZT21) reveals a 453 amino acid protein with characteristics consistent with ciliary/flagellar associated proteins, including potential coiled-coil regions and protein interaction domains.

Key Findings

1. Protein Properties

• Length: 453 amino acids
• Molecular Weight: ~57.6 kDa
• Theoretical pI: Basic (>7.0)
• Charge distribution: 45 basic residues vs 34 acidic residues

2. Structural Features

Coiled-Coil Regions

• Multiple potential coiled-coil regions detected
• Major coiled-coil domain spanning positions 0-259 (high confidence)
• Additional regions at positions 273-315 and 350-441
• Consistent with protein-protein interaction and structural roles

Domain Predictions (Pattern-based)

• 4 potential WD40-like repeat patterns detected
• 6 potential TPR-like motifs identified
• Note: These are simplified predictions requiring validation with HMM-based tools

3. Ciliary Localization Signals

• 3 VxPx-like motifs detected
• No canonical RVxP ciliary targeting signals found
• Pattern consistent with ciliary/flagellar localization (CFAP family)

4. Composition Analysis

• Proline content: 4.2% (normal range)
• Glycine content: 6.6% (slightly elevated)
• Serine content: 8.4% (elevated, potential phosphorylation sites)

Functional Implications

1. Ciliary/Flagellar Function: Name (CFAP = Cilia and Flagella Associated Protein) and sequence features support ciliary localization

2. Protein-Protein Interactions: Extensive coiled-coil regions suggest roles in protein complex formation

3. Structural Role: Large size and coiled-coil architecture indicate potential structural/scaffolding function

Limitations and Recommendations

Current Analysis Limitations:

• Pattern-based domain predictions are approximate
• Coiled-coil prediction uses simplified algorithm
• No structural modeling performed

Recommended Follow-up Analyses:

1. InterProScan for comprehensive domain annotation
2. COILS or Paircoil2 for refined coiled-coil prediction
3. AlphaFold structure prediction for 3D modeling
4. Ciliary proteomics database cross-reference

Methods

• Sequence retrieved from UniProt (Q6ZT21)
• Coiled-coil prediction: Heptad repeat pattern analysis
• Domain detection: Regular expression pattern matching
• Molecular weight: Sum of amino acid weights
• pI estimation: Basic/acidic residue ratio

Script

• analyze_cfap418.py - Performs all analyses described above

References

• UniProt Q6ZT21
• Pattern definitions based on PROSITE patterns

Quality Checklist

• [x] Scripts present and executable
• [ ] Scripts accept command-line arguments (hardcoded UniProt ID Q6ZT21)
• [ ] Scripts can analyze other proteins (some CFAP-specific assumptions in analysis)
• [x] Results are reproducible
• [x] Methods clearly documented
• [x] Conclusions supported by evidence
• [ ] No hardcoded values (hardcoded UniProt ID Q6ZT21, CFAP family assumptions)
• [x] Output files generated as described